Torch with integral flashback arrestor and thermal shut-off device

ABSTRACT

A torch with integral flashback arrestor and thermal shut-off device is provided. In one approach, a torch body includes a passageway of the torch body, and a cartridge assembly disposed within the passageway. The cartridge assembly may include at least one of: a resettable pressure-sensitive device, and a thermal shut-off device, wherein the pressure-sensitive device and the thermal shut-off device are modifiable from a first configuration to a second configuration in response to a pressure or temperature gradient in the torch body, and wherein the second configuration restricts flow through the passageway. The cartridge may further include a check valve disposed along the passageway, for example, within a bore of a bushing, or within a retainer coupled to the torch body at an inlet of the passageway.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/US2016/069392, filed on Dec. 30, 2016, the entire contents of which is hereby incorporated by reference.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to cutting, welding, and heating devices and, more particularly, to cutting torches with flashback arrestors.

Discussion of Related Art

Oxygen-fuel cutting, welding, or heating devices discharge fuel gas and oxygen from a nozzle for cutting, welding, or heating purposes. A typical torch includes a control body for connecting to separate fuel gas and oxygen supplies, tubes for supplying the oxygen and fuel gas from the control body to a head, and a cutting tip mounted to the head. The cutting tip receives the fuel gas and oxygen from the head and discharges these gases from its nozzle. More specifically, the head includes an interior surface extending around and defining a head cavity, an oxygen port that is open to the head cavity for supplying oxygen to the head cavity, and a fuel gas port that is open to the head cavity for supplying fuel gas to the head cavity. The cutting tip includes multiple passageways for directing the gases from the head to the nozzle.

In one previous approach, a conventional cutting torch first generates a preheat flame with gases discharged from the nozzle, and the preheat flame is used to heat a metal workpiece. After the preheat flame has heated the workpiece sufficiently, a high velocity cutting oxygen stream is activated and delivered through the nozzle. The high velocity cutting oxygen stream physically removes molten material of the workpiece by oxidation, to cut the workpiece. Typically, a number of valves and related components are provided upstream of the nozzle, such as in the control body, to control the operations of the cutting torch.

Flashback is regression of the flame through the torch toward the gas supply, and can propagate through the torch and welding hose. Flashback may be caused by mixed gases (e.g., fuel/oxygen) that are allowed to develop within the welding hose due operator error, improper gas pressure, and/or defective equipment. More specifically, in some cases, improper procedure/operation can result in reverse flow of oxygen into the fuel hose or reverse flow of fuel into the oxygen hose leading to mixed gas (e.g., flammable gas) within either hose. Due to the rapid and explosive nature of flashback, it poses a major safety hazard to the operator of the gas torch and can damage the gas torch and associated equipment.

Previous approaches for addressing flashback include the use of a sintered material within the torch to be used at the entry point of the gases into the torch. Although this stops the flashback from traveling upstream from the components that supply the gas to the torch, it disadvantageously does not eliminate the effects of flashback within the torch itself. As a result, the torch can still be damaged or the operator can be injured by flashback within the torch.

In another previous approach, packing material may be installed into the head of a torch or in a tube that is immediately upstream from the head for arresting flashback. However, this packing material may become damaged, such as by becoming clogged with carbon deposits resulting from flashback. As a result, the packing material must be periodically replaced. Disadvantageously, the removal and replacement of packing material in cutting torches is labor intensive. Additionally, and of significant safety importance, if the packing material is not properly packed it may not perform its intended function, which can result in damage to the torch or injury to its operator.

In yet another previous approach, a check valve may be installed in each of the oxygen and fuel passageways to allow the oxygen and the fuel to flow in one direction, while preventing the reverse flow. Check valves, however, are mechanical devices that may become unreliable when contaminated with dirt or debris, which can cause the check valve to leak. Moreover, the check valves cannot prevent flashback flame from propagating upstream once flashback occurs.

SUMMARY OF THE DISCLOSURE

In an exemplary approach according to the disclosure, a torch body may include a passageway, and a cartridge assembly disposed within the passageway. The cartridge assembly may include at least one of: a resettable pressure-sensitive device, and a thermal shut-off device, wherein the pressure-sensitive device and the thermal shut-off device are modifiable from a first configuration to a second configuration in response to a pressure or temperature gradient in the torch body, and wherein the second configuration restricts flow of a gas through the passageway. The cartridge assembly may further include a bushing operable with at least one of: the pressure-sensitive device and the thermal shut-off device, and a check valve positioned along the passageway of the torch body, the check valve operable with at least one of: the resettable pressure-sensitive device or the thermal shut-off device.

In another exemplary approach of the disclosure, a flashback arrestor may include a passageway of a torch body and a resettable pressure-sensitive device operable with the bushing, wherein the resettable pressure-sensitive device is modifiable from a first configuration to a second configuration in response to a pressure change in the torch body, and wherein the second configuration causes actuation of a piston within the passageway to prevent back-flow through the passageway. The flashback arrestor may further include a check valve disposed within the passageway.

In another exemplary approach of the disclosure, a torch may include a torch body and a flashback arrestor disposed within a passageway of the torch body. The flashback arrestor may include a thermal shut-off device modifiable from a first configuration to a second configuration in response to a temperature gradient in the torch body, wherein the second configuration restricts flow of a gas through the passageway. The flashback arrestor may further include a retainer coupled to the torch body at an inlet of the passageway, a bushing coupled to the retainer, and a check valve disposed within the retainer.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate exemplary approaches of the disclosed torch handle including a torch and flashback arrestor so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a side partial cutaway view of a flashback arrestor mounted within a torch body according to exemplary approaches of the disclosure;

FIG. 2 is a perspective view of the flashback arrestor of FIG. 1 according to exemplary approaches of the disclosure;

FIG. 3 is an exploded perspective view of the flashback arrestor of FIG. 2 according to exemplary approaches of the disclosure;

FIG. 4 is a side perspective view of a stem and adaptor of the flashback arrestor of FIG. 2 according to exemplary approaches of the disclosure;

FIG. 5 is side cutaway view of the flashback arrestor of FIG. 1 according to exemplary approaches of the disclosure;

FIG. 6 is a side partial cutaway view of a flashback arrestor mounted within a torch body according to another exemplary approach of the disclosure;

FIG. 7 is perspective view of a resettable pressure-sensitive device within the torch body of FIG. 6 according to exemplary approaches of the disclosure;

FIG. 8 is a partial cutaway side view of the resettable pressure-sensitive device of FIG. 7 in a first configuration according to exemplary approaches of the disclosure; and

FIG. 9 is a partial cutaway side view of the resettable pressure-sensitive device of FIG. 7 in a second configuration according to exemplary approaches of the disclosure.

The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. Furthermore, the drawings are intended to depict exemplary embodiments of the disclosure, and therefore is not considered as limiting in scope.

Furthermore, certain elements in some of the figures may be omitted, or illustrated not-to-scale, for illustrative clarity. The cross-sectional views may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines otherwise visible in a “true” cross-sectional view, for illustrative clarity. Furthermore, for clarity, some reference numbers may be omitted in certain drawings.

DESCRIPTION OF EMBODIMENTS

The present disclosure will now proceed with reference to the accompanying drawings, in which various approaches are shown. It will be appreciated, however, that the disclosed torch and flashback arrestor may be embodied in many different forms and should not be construed as limited to the approaches set forth herein. Rather, these approaches are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, like numbers refer to like elements throughout.

As used herein, an element or operation recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or operations, unless such exclusion is explicitly recited. Furthermore, references to “one approach” or “one embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional approaches and embodiments that also incorporate the recited features.

Furthermore, spatially relative terms, such as “beneath,” “below,” “lower,” “central,” “above,” “upper,” “proximal,” “distal,” and the like, may be used herein for ease of describing one element's relationship to another element(s) as illustrated in the figures. It will be understood that the spatially relative terms may encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

As disclosed herein, embodiments of the disclosure provide a torch with integral flashback arrestor and thermal shut-off device. In some approaches, a torch body includes a passageway of the torch body, and a cartridge assembly disposed within the passageway. The cartridge assembly may include a number of different arrangements. For example, in one arrangement, the cartridge assembly may include a thermal shut-off combined with a flashback arrestor (e.g., a sintered filter/bushing) and, optionally, a check valve. In a second arrangement, the cartridge assembly may include a pressure sensitive switch combined with a check valve and, optionally, a flashback arrestor. In a third arrangement, the cartridge assembly may include a thermal shut off combined with a flashback arrestor, a pressure sensitive switch, and a check valve.

As a result, embodiments of the disclosure provide a built-in design that makes the torch inoperable without the thermal shut-off device and filter element/bushing or, alternatively, without the resettable pressure-sensitive device and the check valve. The torch utilizes a parts-in-place principle in which, unlike prior approaches, a user may be unable to operate the torch without the safety features in place. Thus, the built-in design offers additional security and safety.

Referring now to FIG. 1, a torch body of a torch according to exemplary embodiments will be described in greater detail. As shown, the torch body 100 defines an oxygen passageway 102 and a fuel gas passageway 104, wherein the oxygen passageway 102 is configured to receive a flow of oxygen and the fuel gas passageway 104 is configured to receive a flow of gas during operation of the torch 101 (partially shown). Hereinafter, embodiments of the disclosure will only be discussed with respect to the oxygen side of the torch body for the sake of brevity. However, it will be appreciated that the fuel side may have identical components but with left-hand threads instead of right-hand threads.

Shown within the oxygen passageway 102 is a flashback arrestor (FBA) 110 provided to stop a flashback within the torch body 100, as will be described in greater detail herein. The FBA 110 may include a cartridge assembly 112 disposed within the oxygen passageway 102 of the torch body 100 via a retainer 116, which is coupled to the torch body 100, e.g., by a distal threaded portion 118. In some embodiments, the retainer 116 may be held in place by a retaining plate (not shown), which may be secured to the torch body 100 by a screw and lock washer, for example. The retainer 116 may house therein a check valve 120 at an inlet of the oxygen passageway 102.

With reference now to FIGS. 1-3, the FBA 110 according to exemplary embodiments of the disclosure will be described in greater detail. As shown, the FBA 110 includes a porous or sintered metal filter 124 coupled to the retainer 116, for example, by a press-fit. The retainer 116 includes a bore 126 receiving the check valve 120, the bore 126 in fluid communication with an inlet of the oxygen passageway 102. The retainer 116 includes a proximal threaded portion 130 and the distal threaded portion 118. The check valve 120 is disposed in the bore 126 proximate the proximal threaded portion 130. The proximal threaded portion 130 has an outside diameter and functions as a hose connector for connecting to an oxygen hose (not shown). The check valve 120 is open during normal operation of the torch, allowing oxygen to flow from the hose through the check valve 120 through the torch to the cutting tip. If a reverse flow situation develops, the check valve 120 is designed to close, in most instances, to reduce the possibility of reverse flow of gas from the torch handle into the hose.

As shown, the distal threaded portion 118 of the retainer 116 engages an inner surface of the torch body 100, for example, a threaded surface 119, to secure the flashback arrestor 110 to the torch body 100. In some embodiments, the distal threaded portion 118 has an outside diameter greater than the outside diameter of the proximal threaded portion 130. Furthermore, in some embodiments, an O-ring 132 is disposed in an annular groove 134 of the retainer 116 to prevent leakage of gas from the oxygen passageway to outside the flashback arrestor 110 when the retainer 116 is installed in the torch body 100.

In exemplary embodiments, the sintered filter 124 of the flashback arrestor 110 is, in one form, a porous cylindrical body or bushing, and is formed by a sintering process. The sintered filter 124 defines a proximal end portion 135, a distal end portion 136, and a bore 138 extending therebetween. The bore 138 of the sintered filter 124 is in fluid communication with the bore 126 of the retainer 116. The sintered filter 124 may be press-fitted into the retainer 116 proximate the distal threaded portion 118 at the distal end of the retainer 116. In exemplary embodiments, the sintered filter 124 defines a plurality of pores, wherein the bore 138 of the sintered filter 124 is in fluid communication with the oxygen passageway 102 through the pores of the sintered filter 124. The pores may have irregular shapes and define passageways through the porous sintered filter 124 for extinguishing a flashback through the torch body 100.

Referring now to FIGS. 2-5, the FBA 110 according to exemplary embodiments will be described in greater detail. As shown, the FBA 110 further includes a thermal shut-off device 140 modifiable from a first configuration to a second configuration in response to a pressure and/or temperature gradient in the torch body 100 so as to restrict flow of a fluid through the oxygen passageway 102 of the torch 101. In some embodiments, the thermal shut-off device 140 includes a thermally reactive component, such as a thermal plug or a resettable bi-metallic strip, which changes state in response to a temperature gradient (e.g., a rapid increase caused by a flashback) to permit or restrict the flow of oxygen through the oxygen passageway 102 (FIG. 1).

As shown, the thermal shut-off device 140 may include an adaptor 148 having a plurality of openings 142 and a central opening 144 formed through an end wall 146 thereof, the plurality of openings 142 permitting oxygen to flow from the adaptor 148 during normal operation. The adaptor 148 is configured to engage a guide 152 of the thermal shut-off device 140 such that a first section 154 of the adaptor 148 abuts a rim 156 of the guide 152, and a second section 158 of the adaptor 148 extends into an internal area 160 of the guide 152. The guide 152 may have a generally frusto-conical shaped first section 161 and a generally cylindrical shaped second section 163, wherein the second section 163 is configured to extend within the bore 138 of the sintered filter 124. The first section 161 of the guide 152 further includes a flange 151 having an O-ring 153 extending around a circumference thereof.

The thermal shut-off device 140 may further include a stem 162 and a spring 157 positionable within the internal area 160 of the guide 152. In some embodiments, the stem 162 includes a sealing device 164, such as a flange 165 with groove/O-ring 166, separating first and second elongate members 167, 168. As shown, the first elongate member 167 may be a cylindrical element extending from a first side of the sealing device 164 and into the internal area 160 of the guide 152, and the second elongate member 168 may be a cylindrical element extending from an opposite side of the sealing device 164 towards the central opening 144 of the adaptor 148. A thermal component 170 may be formed around the second elongate member 168 for separating the adaptor 148 from the stem 162 under normal operating conditions. In some non-limiting embodiments, a diameter of the first elongate member 167 is greater than a diameter of the second elongate member 168.

During normal operating conditions, the adaptor 148 is separated from the stem 162 by the thermal component 170, which is present around the second elongate member 168 of the stem 162 in the first configuration of the thermal shut-off device 140. In some embodiments, the thermal component 170 is a polymer (e.g., plastic) or a lead plug having a pre-specified melting point to allow the thermal component 170 to melt in response to a high temperature event within the torch head 100, such as sustained backfire. Once melted, the thermal shut-off device 140 enters the second configuration in which the stem 162 is permitted to engage the adaptor 148 in response to a force from the spring 157, thereby preventing flow of a gas through the plurality of openings 142 of the adaptor 148.

In other embodiments, the thermal component 170 is an elastic or resettable bi-metallic strip designed in such a way that in a normal position it keeps the flow passages open, but when actuated allows the spring force of the sealing mechanism to close the flow passage. In some embodiments, the bi-metallic strip expands in response to a higher temperatures, thus separating itself from the first elongate member 167 and allowing the stem 162 to engage the adaptor 148 in response to a force from the spring 157. The second elongate member 168 then moves into the central opening 144, which prevents flow of a fluid through the plurality of openings 142 of the adaptor 148. As the bi-metallic strip cools down and contracts, it forces the stem 162 away from the adaptor 148, thus allowing gas to again flow through the plurality of openings 142 of the adaptor 148.

Turning now to FIG. 5, a cross-sectional view of the thermal shut-off device 140 will be described in greater detail. As shown, the thermal shut-off device 140 may be inserted into a cavity 172 of the oxygen passageway 102 of the torch body 100 until the adaptor 148 makes contact with an end wall 173 defining a distal portion of the cavity 172. The first section 154 of the adaptor 148 may have a diameter greater than that of the second section 158 of the adaptor 148, thus causing the first section 154 of the adaptor 148 to engage the rim 156 of the first section 161 of the guide 152, and allowing the second section 158 of the adaptor 148 to extend into the guide 152.

In exemplary embodiments, the O-ring 153 of the first section 161 of the guide 152 forms a seal with an inner sidewall 175 of the cavity 172. The guide 152 includes the plurality of openings 150 formed through a sidewall of the first section 161, thereby allowing flow between the internal area 160 of the guide 152 and a fluid channel 177, which is defined by the O-ring 153, the sintered filter 124, and the retainer 116, shown threaded into the torch body 100. A shoulder 178 defining the intersection of the first and second sections 161, 163 of the guide 152, may be in abutment with a distal end surface 179 of the sintered filter 124, as shown.

The second section 163 of the guide 152 extends within the bore 138 of the sintered filter 124, and includes a proximal end wall 180, a first sidewall section 181, and a second sidewall section 182. A sloped wall 183 extending between the first sidewall section 181 and the second sidewall section 182 is configured to engage the flange 165 of the stem 162 to limit movement of the stem 162 in a proximal direction towards the retainer 116. The O-ring 166 of the stem 162 engages an inner surface of the first sidewall section 181 to form a seal therebetween.

In some embodiments, the spring 157 is provided within an interior 184 of the stem 162, and engages the proximal end wall 180. During use, the spring 157 presses against the flange 165 of the stem 162, which in turn presses against the adaptor 148 via the thermal component 170. Specifically, the thermal component 170 and the second elongate member 168 are biased towards the central opening 144 of the adaptor 148. When present, the thermal component 170 separates the stem 162 from the adaptor 148, thereby preventing the second elongate member 168 from extending fully into the central opening 144 of the adaptor 148. In the event of an increased temperature occurs within the torch body 100, the thermal component 170 is designed to melt, thus causing the thermal shut-off device 140 to transform to the second configuration (not shown) in which the second elongate member 168 is permitted to enter the central opening 144 and extend into a cavity 186 beyond the distal end of the adaptor 148. This causes a distal end surface 190 of the flange 165 of the stem 162 to cover the plurality of openings 142 through the adaptor 148, and the O-ring 166 of the stem 162 to move from a first position against the inner surface of the first sidewall section 181, as shown, to a second position against an inner sidewall surface 191 of the second section 158 of the adaptor 148. The O-ring 166 creates a seal with the inner sidewall surface 191, thereby preventing flow of gas through the plurality of openings 142 of the adaptor 148, and disabling the torch 101.

Although not shown, it will be appreciated that in another embodiment, the thermal shut-off device 140 is a solenoid valve in communication with an electronic switch. The solenoid valve may be disposed within the torch body 100, and the electronic switch is configured to send a signal to close the solenoid valve in the case a sensor operable with the electronic switch detects a flow of electrons above a predetermined temperature. The electronic switch may function in a similar fashion to the adaptor and stem described herein, but instead of a mechanical interface for preventing flow, the electronic switch senses the flow of electrons using, e.g., a thermocouple or thermopile, and sends a signal to shut down the solenoid valve provided in the torch flow path. Once the temperature has decreased, the electronic switch senses a reduced flow of electrons, causing the valve to reopen.

Referring now to FIGS. 6-9, a resettable pressure sensitive device within a torch body 200 according to exemplary embodiments of the disclosure will be described. As shown, the torch 201 includes many of the features previously described in relation to the torch 101 shown in FIG. 1 and, as such, may not be described in detail hereinafter for the sake of brevity. In this embodiment, the torch body 200 may include a resettable pressure sensitive device (PSD) 241, such as a piston actuable in response to a back-flow pressure increase within the oxygen passageway 202. In one embodiment, the PSD 241 is secured within the oxygen passageway 202 of the torch body 200 via a retainer 216, which is coupled to the torch body 200, e.g., by a proximal threaded connection 218. In some embodiments, the retainer 216 may be held in place by a retaining plate (not shown), which may be secured to the torch body 200 by a screw and lock washer, for example.

As shown, the PSD 241 includes a main body 243, which may be a piston, having a first O-ring 245 and a second O-ring 247 extending around a circumference thereof and engaging an inner sleeve 249. The main body 243 and an outer sleeve 285 are biased towards a distal end 239 by an inner spring 287 and an outer spring 289, respectively. In some embodiments, a distal end 244 of the main body 243 extends into the proximal end portion 235 of the sintered filter 224. A proximal end 237 of the PSD 241 may include external threading 255 (FIG. 6) for engaging a hose (not shown), while the distal end 239 of the PSD 241 may couple to the torch body 200 via the retainer 216 and threading 219, or be coupled directly to the torch body 200 via a threaded connection in the case no retainer is present.

In a first configuration, i.e., during normal operation, one or more locking balls 293 are maintained along an outer surface 294 of the main body 243 within an opening 295 of the inner sleeve 249, for example, as best shown in FIG. 7. In some embodiments, a portion of the locking ball 293 may extend into an opening 296 between the inner sleeve 249 and the outer sleeve 285. In the event of a flashback, represented by a reverse gas flow 297 shown in FIGS. 8-9, the flashback forces the main body 243 towards the proximal end 237, thus compressing the inner spring 287 and causing the locking ball 293 to enter a recess or groove 298 of the main body 243. As shown, as the locking ball 293 moves into the groove 298 and away from the opening 296 between the inner sleeve 249 and the outer sleeve 285, the outer sleeve 285 is permitted to move towards the distal end 239 by a force from the outer spring 289. The locking ball 293 is therefore confined to the groove 298 by the outer sleeve 285 and the sidewalls of the opening 295 of the inner sleeve 249. Once in place, the locking ball 293 prevents movement of the main body 243 relative to the inner sleeve 249, ceasing gas flow through the PSD 241. In some embodiments, the PSD 241 remains in the closed, second configuration until manually reset by an operator, for example by sliding the outer sleeve 285 towards the proximal end 237, which allows the locking ball 293 to move into the opening 296 and out of the groove 298, thus permitting the main body 243 to move towards the distal end 239.

In some embodiments, a check valve 220, which is designed to allow flow in only one direction, is provided along the oxygen passageway 202 of the torch body 200, for example, within the bore 238 of the sintered filter 224. The check valve 220 is typically open during normal operation of the torch 101, allowing oxygen to flow from the hose through the check valve 220, through the torch 201, and to the cutting tip. If a reverse flow situation develops, the check valve 220 is designed to close, for example, by engaging the distal end 244 of the main body 243, thus reducing the possibility of reverse flow of gas. In exemplary embodiments, the check valve 220 is positioned between the thermal shut-off device 240 and the PSD 141. As shown, the check valve may 220 abut the proximal end wall 280 of the second section 263 of the guide 252, which extends within the bore 238 of the sintered filter 224.

While the present disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof. While the disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the spirit and scope of the disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof. 

What is claimed is:
 1. A torch body comprising: a passageway; and a cartridge assembly disposed within the passageway, the cartridge assembly comprising: at least one of: a resettable pressure-sensitive device, and a thermal shut-off device, wherein the resettable pressure-sensitive device and the thermal shut-off device are modifiable from a first configuration to a second configuration in response to a pressure or temperature gradient in the torch body, and wherein the second configuration restricts flow of a gas through the passageway; a bushing operable with at least one of: the pressure-sensitive device and the thermal shut-off device; and a check valve positioned along the passageway of the torch body, the check valve operable with at least one of: the resettable pressure-sensitive device or the thermal shut-off device.
 2. The torch body of claim 1, wherein the bushing is a sintered filter press fitted within a bore of the cartridge assembly.
 3. The torch body of claim 1, the thermal shut-off device comprising: a guide received within an internal bore of a bushing; a stem positioned within an internal area of the guide; and an adaptor separated from the stem by a thermal component, wherein the adaptor has a plurality of openings through an end wall, and wherein the second configuration causes the stem to engage the adaptor to prevent flow of the gas through the plurality of openings through the end wall.
 4. The torch body of claim 3, the stem comprising: a first elongate member extending from a first side of a sealing device and into an internal area of the guide; and a second elongate member extending from a second side of the sealing device and towards a central opening of the adaptor.
 5. The torch body of claim 3, wherein the guide includes a set of openings formed through a sidewall.
 6. The torch body of claim 3, the thermal shut-off device further comprising a spring disposed within the stem for actuating the stem towards the adaptor.
 7. The torch body of claim 6, wherein the thermal component is one of: a thermal plug made from a polymer configured to melt at a predetermined temperature to bring the adaptor in contact with a flange of the stem, and a resettable bi-metallic strip permitting flow of the gas to the adaptor in the first configuration, and permitting the spring to actuate the stem towards the adaptor in the second configuration.
 8. The torch body of claim 7, wherein the second elongate member extends through the central opening of the adaptor in the case that the thermal plug melts and the adaptor is brought into contact with the sealing device of the stem.
 9. The torch body of claim 1, wherein the resettable pressure-sensitive device is a piston actuated in response to an increase in back-flow pressure within the passageway.
 10. The torch body of claim 1, wherein the check valve is disposed within a retainer coupled to the torch body at an inlet of the passageway.
 11. The torch body of claim 1, wherein the check valve is disposed within check is provided within a bore of the bushing.
 12. A flashback arrestor comprising: a passageway of a torch body; a resettable pressure-sensitive device disposed along the passageway, wherein the resettable pressure-sensitive device is modifiable from a first configuration to a second configuration in response to a pressure change in the torch body, and wherein the second configuration causes actuation of a piston within the passageway to prevent back-flow through the passageway; and a check valve disposed within the passageway.
 13. The flashback arrestor of claim 12, the resettable pressure-sensitive device comprising: an inner sleeve biased by an inner spring; an outer sleeve biased by an outer spring; and a locking ball positioned along an outer surface of a main body of the piston within an opening of the inner sleeve, wherein a portion of the locking ball extends into an opening between the inner sleeve and the outer sleeve when the resettable pressure-sensitive device is in the first configuration, and wherein the locking ball extends into a groove of the main body when the pressure-sensitive device is in the second configuration.
 14. The flashback arrestor of claim 12, further comprising a thermal shut-off device including: a guide received within an internal bore of the passageway; a stem positioned within an internal area of the guide; and an adaptor separated from the stem by a thermal component, wherein the adaptor has a plurality of openings through an end wall, and wherein the second configuration causes the stem to engage the adaptor to prevent flow of a gas through the plurality of openings through the end wall.
 15. The flashback arrestor of claim 14, the stem comprising: a first elongate member extending from a first side of a sealing device and into an internal area of the guide; a spring disposed within the first elongate member for actuating the stem towards the adaptor; and a second elongate member extending from a second side of the sealing device and towards a central opening of the adaptor.
 16. The flashback arrestor of claim 15, wherein the thermal component is one of: a thermal plug made from a polymer configured to melt at a predetermined temperature to bring the adaptor in contact with a flange of the stem, and a resettable bi-metallic strip permitting flow of the gas to the adaptor in the first configuration, and permitting the spring to actuate the stem towards the adaptor in the second configuration.
 17. The flashback arrestor of claim 16, wherein the second elongate member extends through the central opening of the adaptor in the case that the thermal plug melts and the adaptor is brought into contact with the sealing device of the stem.
 18. A torch comprising: a torch body; and a flashback arrestor disposed within a passageway of the torch body, the flashback arrestor comprising: a thermal shut-off device modifiable from a first configuration to a second configuration in response to a temperature gradient in the torch body, wherein the second configuration restricts flow of a gas through the passageway; a retainer coupled to the torch body at an inlet of the passageway; a bushing coupled to the retainer; and a check valve disposed within the retainer.
 19. The torch of claim 18, the thermal shut-off device comprising: a guide received within an internal bore of the bushing; a stem positioned within an internal area of the guide; and an adaptor separated from the stem by a thermal component, wherein the adaptor has a plurality of openings through an end wall, and wherein the stem engages the adaptor to prevent flow of the gas through the plurality of openings through the end wall in the second configuration.
 20. The torch of claim 19, the stem comprising: a first elongate member extending from a first side of a sealing device and into an internal area of the guide; a spring disposed within the first elongate member for actuating the stem towards the adaptor; and a second elongate member extending from a second side of the sealing device and towards a central opening of the adaptor.
 21. The torch of claim 20, wherein the thermal component is one of: a thermal plug made from a polymer configured to melt at a predetermined temperature to bring the adaptor in contact with the sealing device of the stem, and a resettable bi-metallic strip permitting a flow of gas to the adaptor in the first configuration, and permitting the spring to actuate the stem towards the adaptor in the second configuration.
 22. The torch of claim 21, wherein the second elongate member extends through the central opening of the adaptor in the case that the thermal plug melts and the adaptor is brought into contact with the sealing device of the stem. 